The present application is the U.S. national stage application of International Application PCT/GB99/00514, filed Feb. 18, 1999, which international application was published on Aug. 26, 1999 as International Publication WO 99/43109. The International Application claims priority of Great Britain Patent Application 9803623.9, filed Feb. 20, 1998.
The present invention relates to the transmission of audio information and to both a method and system for such transmission.
It is known to broadcast data along with audio signals in order to provide interruption of the broadcast audio signal by causing the receiver to retune automatically to a different frequency to receive alternative information such as news or traffic information. The Radio Data System (RDS) has been used for such purpose in Europe for several years. However, although the user is able to select for interruption between certain general types or categories of information, once this selection has been made by the user, the timing of interruption and the information provided are automatically determined by the service providing the information and to which the radio retunes. Whilst such a service is very valuable, it is limited in nature.
It is known eg from GB-A-2 313 981, EP-A-0 804 012 and WO-A-95-12929 to utilise a GSM or similar cellular radio link to instruct the playing of selected music, video or multi-media material from a remote source to the user via, for example a DAB or other broadcast signal. In order to provide a wider range of information to a radio user, a different system is necessary.
According to the present invention there is provided a method for transmitting audio information to a receiver, comprising: transmitting from a first source to the receiver first audio information together with other information comprising addressing data; selectively transmitting from the receiver to a service provider a data signal dependent on the addressing data; matching the data signal received at the service provider with respective further audio information; transmitting the respective further audio information from a second source to the receiver.
The invention also includes a system for transmitting audio information to a receiver, comprising:
a first source for transmitting to the receiver first audio information together with other information comprising addressing data;
means at the receiver for converting the first audio information to an audio signal;
means at the receiver selectively operable for transmitting to a service provider a data signal dependent on the addressing data;
comparing means for matching the data signal received at the service provider with respective further audio information;
a second source for transmitting the respective further audio information from the service provider to the receiver; and,
means at the receiver for converting the further audio information to an audio signal.
By this method and system a web of recursively linked audio material may selectively be provided to a user of the receiver through the use of appropriate keys at the receiver. The system may be operated by the user to provide further audio information related to the first audio information by extracting the addressing data and transmitting a corresponding data signal, via say a digital mobile telephone network, to a service provider system at which the received addressing data is matched, using a database, with further audio information related to the first audio information, and that further audio information is then transmitted to the receiver. A further key may be used to return the listener to the original audio information transmission or to the previous one.
The system of the invention may use a conventional RDS system to provide the transmission of the further audio information, by causing a transmitter (source) related to the first transmitter (source) to interrupt the reception of the first audio information with the further audio information, but preferably, the system makes use of digital audio broadcasting (DAB) signals to provide the first audio information signal and related addressing data and the further audio information and further addressing data are transmitted by a DAB transmitter related to the transmitter providing the first audio information and addressing data, or else by the mobile telephone link used to transmit the addressing data-related signal to the service provider.
However, the invention is not limited to particular mechanisms or types of transmission of either the audio information and related addressing data nor of the addressing data-related data signal and these could be provided by wireless, wire or cable links. For example the original transmission could be an audio information signal (together with related addressing data) transmitted by an Internet web site.
In order to indicate to a user that there is further audio information related to the first (or subsequent) audio information provided to the user, the audio signal is augmented. This may be achieved in a number of ways and the augmentation may, depending on the method chosen, occur either at the source (ie. to the transmitted audio information) or else at the receiver (ie. to the received audio information before conversion). For example a beep may be inserted at the beginning and end of sections of audio information transmission to indicate to a listener that what follows is capable of being linked to to provide further information. Alternatively, audio processing may be used to give the converted audio signal a particular auditory shade or style. A further possibility is to provide a visual indication on a visual display panel associated with the receiver.
When the user has selected or linked to further audio information, the converted audio signal needs to be separated from the original audio signal to indicate that the listener is now linked to additional material. This may be done in a number of ways. For example, the transmission of audio information may be paused momentarily to indicate the change of content. Alternatively, the audio signals may be superimposed, with the further audio information being more prominent than the original. A still further possibility is to separate the original and further audio signals to left and right stereo channels, with suitable mixing down of the original signal from stereo to mono if necessary. The various type of separation may be selected by the user and they may be combined if desired, the required circuitry for the different types being provided within the receiver.